SMC Networks 7004VBR User Manual page 49

A S
DVANCED ETUP
The Intrusion Detection feature of the Barricade limits the access of the
incoming traffic from the WAN port. When the SPI feature is turned on,
all the incoming packets will be blocked unless certain types of traffic types
are checked by the users. When the user checkes certain types of traffic,
only the particular type of traffic initiated from the Internal LAN will be
allowed. For example, if the user only checks "FTP service" from the
Stateful Packet Inspection page, all the incoming traffic will be blocked
except the FTP connection initiated from the local LAN.
• Stateful Packet Inspection
This option allows you to select different application types that are using
dynamic port numbers. If you need to use the Stateful Packet Inspection
(SPI) for blocking packets, click on the "Yes" radio button in the "Enable
SPI and Anti-DoS firewall protection" field and then check the inspection
type that you need, such as Packet Fragmentation, TCP Connection, UDP
Session, FTP Service, H.323 Service and TFTP Service.
• Hacker Prevention Feature
The Barricade firewall inspects packets at the application layer, and
maintains TCP and UDP session information, including timeouts and
number of active sessions, provides the ability to detect and prevent certain
types of network attacks such as DoS attacks.
Network attacks that deny access to a network device are called
denial-of-service (DoS) attacks. Denials of Service (DoS) attacks are aimed
at devices and networks with a connection to the Internet. Their goal is
not to steal information, but to disable a device or network so users no
longer have access to network resource.
4-28